Field of the Invention
The invention relates to a memory and a method of fabricating the same; more particularly, the invention relates to a resistive memory and a method of fabricating the same.
Description of Related Art
In recent years, resistive memories including resistive random access memories (RRAM) have been developed rapidly, have drawn most attention, and may be the most popular memories in the next-generation memory market. Due to the potential advantages of low power consumption, fast operation speed, high density, and compatibility with complementary metal oxide semiconductor (CMOS) manufacturing technologies, the resistive memories can act as the next-generation non-volatile memory devices.
The existing resistive memory often includes an upper electrode and a lower electrode which are arranged opposite to each other and also includes a dielectric layer located between the upper electrode and the lower electrode. Prior to operations of the existing resistive memory, a forming process need be performed, i.e., a relatively high positive bias is applied to the resistive memory, such that oxygen vacancy or oxygen ion is generated in the dielectric layer, and a conductive filament is then formed. In a resetting process, a negative bias is applied to the resistive memory, and accordingly the conductive filament is broken off. At this time, the oxygen vacancy adjacent to the upper electrode is re-filled (or oxygen ion departs from a path of electric current); as a result, the conductive filament is broken off at a location close to the upper electrode. By contrast, in a setting process, a positive bias is applied to the resistive memory, such that the oxygen vacancy or the oxygen ion is generated once more in the dielectric layer, and a new conductive filament is formed again.
In the conventional RRAM manufacturing process, a memory cell is defined by an etching process, and it is likely to form dangling bonds on sidewalls of the memory cell in a plasma treatment step or a wet cleansing step of the etching process. During the resetting process, the dangling bonds are combined with the oxygen vacancy or the oxygen ion, thus resulting in reset failure. Hence, how to provide a resistive memory and a method of fabricating the same to protect the sidewalls of the memory cell, prevent the reset failure, and further enhance high-temperature data retention (HTDR) is one of the crucial research topics in the pertinent field.